The Belgium international has sealed a move to Selhurst Park for the second time in his career, though confirmation of an expected 12-month contract extension with his parent club has not yet been forthcoming.
During his previous spell at Palace, Batshuayi bagged six goals in 13 appearances and Roy Hodgson is now looking to the 26-year-old to solve his side’s goalscoring woes.
The deal does however mean that Palace are unable to loan Blues midfielder Conor Gallagher, who had already undergone a medical with the Eagles, due to Premier League laws dictating that no club can loan two players from the same top-flight side.
Batshuayi becomes Palace’s third signing of the summer after right-back Nathan Ferguson and attacking midfielder Eberechi Eze.
Batshuayi told Crystal Palace’s official website: “I feel like I’m home now, so it’s good. But I need to do a good season here, to work a lot with my teammates and I want to do my best here,”
“It’s not my first time here. I know the teammates, I know the gaffer, I know how the club works here. For me, it’s the best decision.
“I’m happy, the coach is happy, my teammates are happy. Let’s get to work.”